Vortex reactor and method of using it

ABSTRACT

A vortex reactor is provided. The vortex reactor includes a reaction chamber formed by a frustum-shaped portion, the narrower part of which is downwardly oriented. Proximate to the narrower part of the frustum-shaped portion, the vortex reactor includes apparatus for creating an axial gas flow and apparatus for creating a circumferential gas flow. The vortex reactor also includes a particulate solid inlet for feeding particulate solids to the reaction chamber. The vortex reactor may optionally include apparatus for generating plasma in the reaction chamber by providing a gliding arc electrical discharge in the reaction chamber. Also provided is a method of processing particulate solids using the vortex reactor of the invention. A reverse vortex plasma reactor (TSAPG) is also provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to plasma generators and theirapplications in plasma chemistry and technology. In particular, to theprovision of a method of using a fluidized bed with low-temperatureplasma without the use of a grid, the improvement of the efficiency andlifetime of reactors, and the design of electrodes in a Tornado SlidingArc Plasma Generator (TSAPG).

2. Description of the Related Technology

Improving the efficiency of the operation of a fluidized bed remains animportant technological goal, owing to the significant economic benefitsthat result in almost every sector of the economy.

Physical processes that utilize fluidized beds include drying, mixing,granulation, coating, heating and cooling. All these processes takeadvantage of the excellent mixing capabilities of the fluidized bed.Good solids mixing gives rise to good heat transfer, temperatureuniformity and ease of process control. One of the most importantapplications of the fluidized bed is to the drying of solids. Fluidizedbeds are currently used commercially for drying such materials ascrushed minerals, sand, polymers, pharmaceuticals, fertilizers andcrystalline products.

Fluidized beds are often used to cool particulate solids following areaction. Cooling may be by fluidizing air alone or by the use ofcooling water passing through tubes immersed in the bed

Other examples of the application of fluidized bed technology todifferent kinds of chemical reaction are ethylene hydrogenation, sulfideore roasting, combustion, and hydrocarbon cracking. Reasons for usingfluidized beds are the substantially uniform temperature inside the bed,ease of solid handling, and good heat transfer that they provide.

A new approach to the production of Vinyl Acetate Monomer (VAM) is touse a fluidized-bed process in which gas phase reactants are contactedcontinuously over (small-sized) supported catalytic particles underfluidized conditions.

Fluidized beds are also used as sorters in the food processing industry.This technology uses a mobile field separation apparatus that has a dryfluidized bed system with sand as the fluidized medium. The technologycan remove all dirt clumps from the lifted product stream, such as frompotatoes. The technology could be applied to cleaning field tare fromincoming raw food product streams and could be used by industrialprocessors to replace water flumes that consume significant electricalpower and water and require a relatively high degree of maintenance.

Fluidized beds can also be used in gasification systems. The fluid bedconverts, for example, biomass waste products into a combustible gasthat can be fired in a boiler, kiln, gas turbine or other similar deviceas a means to convert a portion of the fuel supply to clean, renewablebiomass fuel. Gasification is the thermal decomposition of organicmatter in an oxygen deficient atmosphere producing a gas compositioncontaining combustible gases, liquids and tars, charcoal, and air, orinert fluidizing gases. Typically, the term “gasification” refers to theproduction of gaseous components.

A gas distributor is a device designed to ensure that the fluidizing gasis always substantially evenly distributed across the cross-section ofthe bed. It is an important part of the design of a fluidized bedsystem. Good design is based on achieving a pressure drop, which is asufficient fraction of the bed pressure drop. Some distributor designsin common use are (a) drilled plate, (b) cap design, (c) continuoushorizontal slots, (d) stand pipe design, and (e) sparge tubes with holespointing downwards.

Loss of fluidizing gas will lead to collapse of the fluidized bed into apacked bed. If the process involves the generation of heat, then thisheat will not be dissipated as well from the packed bed as it was fromthe fluidized bed.

All parts of the fluidized bed unit are subject to erosion by the solidparticles. Heat transfer tubes within the bed or freeboard areparticularly at risk and erosion here may lead to tube failure. Erosionof the distributor may lead to poor fluidization and areas of the bedbecoming de-aerated. Loss of fine solids from the bed reduces thequality of fluidization and reduces the area of contact between thesolids and the gas in the process. In a catalytic process this generallyresults in lower conversion.

In addition, reactors employing a grid for the generation of plasma arealso subject to erosion by contact with solid particulates. Also,generation of plasma using a grid is less energy efficient than othermethods of plasma generation.

In a fluidized bed combustion chamber, known as a spouted bed reactor, acone shaped hopper is continuously fed with solid particles. The solidparticles are suspended briefly and processed in an axial flow of gasoriginating from the bottom or apex of the cone. One disadvantage of thespouted bed reactor is the instability of the axial gas flow. The solidparticles fall out of suspension easily due to turbulence and accumulatein the narrower bottom portion of the cone. In addition, the bottomentry tube provides only an axial gas flow velocity component. Thus,there is no orthogonal gas flow velocity component to assist indistributing the solid particles throughout the cone shaped reactor.Consequently, the mixing of solid particles with gas, and theinteraction among the solid particles, are relatively poor. The poormixing and non-uniform particle distribution result in a relatively lowefficiency of combustion and/or gasification.

In order to improve the distribution of solid particulates throughout acone shaped reactor and, thereby, minimize inefficiencies produced bynon-ideal particle distributions, it is known to utilize acircumferential flow of gas whose direction is orthogonal to the axialgas flow. The axial and circumferential gas flows may preferably beadjusted to produce a vortex in the conical reactor.

U.S. Pat. No. 5,486,269, for example, describes an inverted conicalreactor, suitable for coal gasification, which uses a tangential flow ofair to achieve a vortex flow pattern.

None of these devices and methods, however, provides fluidization ofsolid particulates with optional plasma energy input and withoutemploying a grid. Therefore, there remains a need for a fluidizationreactor with optional plasma energy input that does not employ a grid.

Another application of plasma technology is thermal spray deposition. Aplasma jet generated by a plasma generator accelerates and meltsparticles of the material to be deposited on the substrate. Thistechnology is widely used for the development of hard,corrosion-resistant, thermal barriers and other types of coatings. DCplasma torches used in such plasma generators have a very limitedlifetime because of electrode erosion.

Another application of plasma technology is thermal waste destruction.In this case plasma generators are used as sources of high temperatureand/or chemically active plasma for waste treatment. Also, in some casesplasma generators are used as reactors for waste destruction. In allthese cases, use of cheap and effective DC or AC plasma generators withopen (non-insulated) electrodes is limited by the very limited lifetimeof the electrodes.

Other applications of plasma technology include different plasmachemical processes (decomposition of chemical solutions, oxidation andreduction of different metals, production of nano-particles, surfacetreatment and sterilization, and so on), welding, cutting, etc. In allcases of plasma technology application the key problem related to theuse of cheap and effective DC and AC plasma generators and plasmareactors, is the limited lifetime of the electrodes.

Additionally, reverse vortex (tornado) sliding (or gliding) arc plasmagenerators (TSAPG) with electrodes for DC or AC current have beenrecently developed. Electrodes for TSAPG in current use have complexshapes (spiral or ring). These electrodes are typically submerged in theplasma generator volume, which results in gas flow disturbance andelectrode overheating. Despite the recent development of thesegenerators, the problems with the overall lifetime of the plasmagenerators and the efficiency of the energy use have not been completelysolved. An optimal electrode design has not yet been developed.

Additionally, flame stabilization of lean and super lean fuel and airmixtures for NOx reduction is a key problem for modern gas turbineengines and burners. One of the well-known solutions is utilization ofpilot flames, but existing pilot flames generate too much nitrogenoxide. Utilization of a DC plasma torch for flame stabilization in gasturbine engines works well in the combustion process, but itsapplication is restricted by the limited life cycle of the plasmagenerator electrodes. The electrode design should ensure reliableignition of the arc, long lifetime of the electrodes and absence ofsignificant disturbances of the reverse vortex flow.

Therefore, there remains a need for an electrode design that provides anextended lifetime of the electrodes and increases the energy efficiencyof the system.

SUMMARY OF THE INVENTION

Accordingly, it is an object of certain embodiments of the invention toprovide a fluidization reactor with optional plasma energy input thatdoes not employ a grid.

In order to achieve the above and other objects of the invention, avortex reactor is provided. In one aspect of the invention, the vortexreactor has a reaction chamber including a substantially frustum-shapedportion. The narrower part of the frustrum-shaped portion is downwardlyoriented. The vortex reactor is further equipped with a device forcreating an axial gas flow, and a device for creating a circumferentialgas flow. Also included is a solid particle inlet for introducingparticulate solids into the reactor.

In another aspect of the invention, a method for plasma-assistedprocessing of a solid particulate is provided. In this method, a vortexreactor is provided which includes a substantially frustum-shapedportion. The reactor is provided with a circumferential gas flow and,optionally, with an axial gas flow. Solid particles are added to thereactor, and the particles are processed by reaction with at least oneof the gases. Optionally, generating plasma in at least a portion of thereaction mixture may assist the treatment of solid particulates.

A third aspect of the invention discloses a vortex reactor that has asubstantially cylindrical shaped portion forming a reaction chambertherein. The substantially cylindrical shaped portion forms a firstcharged electrode. An axial flow apparatus is fluidly connected to thereaction chamber for creating an axial fluid flow in the reactionchamber. A circumferential flow apparatus is fluidly connected to thereaction chamber for creating a circumferential fluid flow.

These and various other advantages and features of novelty thatcharacterize the invention are pointed out with particularity in theclaims annexed hereto and forming a part hereof. However, for a betterunderstanding of the invention, its advantages, and the objects obtainedby its use, reference should be made to the drawings which form afurther part hereof, and to the accompanying descriptive matter, inwhich there is illustrated and described a preferred embodiment of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of one embodiment of a vortex spoutedbed reactor.

FIG. 2 is a cross-sectional view of a vortex spouted bed reactor takenalong line II-II of FIG. 1, showing a nozzle arrangement.

FIG. 3 is a cross-sectional view of another embodiment of a vortexreactor equipped for plasma generation.

FIG. 4 is a cross-sectional view of a yet another embodiment of a vortexreactor equipped for plasma generation.

FIG. 5 is a cross-sectional view of a vortex reactor that is cylindricalin shape.

FIG. 6 is a cross-sectional view of another vortex reactor that iscylindrical in shape and has a plurality of electrodes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Several patents are referenced herein in order to illustrate thecontents of the art. Each of these patents is incorporated by referenceas if set forth fully herein.

In general, dimensions, sizes, tolerances, parameters, shapes and otherquantities and characteristics are not and need not be exact, but may beapproximate and/or larger or smaller, as desired, reflecting tolerances,conversion factors, rounding off, measurement error and the like, andother factors known to those of skill in the art. In general, adimension, size, parameter, shape or other quantity or characteristic is“about” or “approximate” as used herein, whether or not expressly statedto be such.

Referring now to the drawings, wherein like reference numerals designatecorresponding structure throughout the views, and referring inparticular to FIG. 1, an embodiment of a vortex spouted bed reactor 500of the present invention is depicted. Vortex spouted bed reactor 500includes a reaction chamber 10 formed by a hollow frustum-shaped portion20. Narrower part 30 of the frustum-shaped portion 20 is downwardlyoriented. A bottom entry tube 35 connects to narrower part 30.Frustum-shaped portion 20 has a top portion 40, to which a reactionchamber extension 50 is optionally attached. Vortex spouted bed reactor500 may optionally include a cap 55. At or near the top of vortexspouted bed reactor 500, there is a particle feeder 90, for introducingsolid particles 80 into reaction chamber 10. An outlet 100 for ash andexhaust gas is also positioned at or near the top of vortex spouted bedreactor 500. One or more additional vortex flow nozzles 120 may also belocated within reaction chamber 10.

In the embodiment shown in FIG. 1, a circumferential gas flow inreaction chamber 10 is produced by introducing a tangential gas flow 65tangential to the walls of bottom entry tube 35 and frustum-shapedportion 20. Tangential gas flow 65 is created by gas flow 32 enteringreaction chamber 10 through one or more nozzles 60 located proximate tonarrower part 30 of frustum-shaped portion 20. The circumferential gasflow produced in reaction chamber 10 becomes a vortex gas flow 38 whencombined with an axial flow of gas 33 from bottom entry tube 35, whichflows through porous bed 70. Vortex gas flow 38 is characterized by anintense swirl or spiral flow with a relatively strong circumferentialcomponent. Solid particles 80 can thus be spread throughout reactionchamber 10 and over the sidewalls of frustum-shaped portion 20. Porousbed 70 located at or near narrower part 30 also functions to retainsolid particles 80 in reactor 500, should they fall from the vortex gasflow 38. Axial gas flow 33 can also help to recirculate fallen solidparticles 80 in reaction chamber 10, thus improving particleinteraction, the uniformity of particle distribution, and reactorefficiency.

Reverse vortex flow nozzles 120 may advantageously be included in vortexspouted bed reactor 500. Reverse vortex flow nozzles 120 are preferablylocated proximate to the top of reactor 500. Reverse vortex flow nozzles120 are positioned to create a reverse vortex flow 39 that moves in thesame direction as vortex gas flow 38 generated by a combination oftangential gas flow 65 and axial gas flow 33. This reverse vortex flow39 helps particles 80 to be recirculated within reaction chamber 10.

Furthermore, vortex spouted bed reactor 500 of the inventionadvantageously provides more effective interaction among solid particles80, gas, and plasma during fluidization processes. This interactionincludes a high degree of mixing among the gas and particles, thusincreasing the yield of the chemical reactions. Processes conducted inreactor 500 are also characterized by increased effective diameter ofgas, and and/or plasma in reaction chamber 10.

Suitable gases for use in the reactor of the present invention include,without limitation, air, oxygen, nitrogen, steam, hydrogen, lowerhydrocarbons, or mixtures of one or more thereof, for example a mixtureof steam and a lower hydrocarbon. In general, a gas is suitable for usein the reactor of the present invention if it comprises a reagent,participates in the fluidization, or if it is inert but can feasiblysupport a plasma or otherwise transfer energy to the reaction mixture.

FIG. 2 depicts a cross-sectional view of a multiple nozzle arrangement,wherein gas enters vortex spouted bed reactor 500 tangentially at 65through four nozzles 60, thereby creating a gas flow tangential to thewalls of bottom entry tube 35 that contributes to providing a vortex gasflow 38 in reaction chamber 10. Vortex gas flow 38 gradually movesupward in reaction chamber 10 with a strong circumferential velocitycomponent. In order to evenly distribute the gas into multiple nozzles60, a gas passage 130 may be used. The number of nozzles 60 employed ina particular reactor is preferably no more than 8, and more preferably,four nozzles 60 are employed.

The multiple nozzle arrangement shown here produces a swirl flow insidethe reactor. Any other device that can generate the swirl flow insidethe reactor can be used. For example, multiple vanes and a spiral shapedpassage can also generate a swirl flow inside the reactor,

Advantageously, porous bed 70 of vortex spouted bed reactor 500 shown inFIG. 1 may be replaced with a flow restrictor 150 that reduces theeffective diameter of bottom entry tube 35 to help retain the solidparticles 80 within reaction chamber 10, and permit sufficient axial gasflow 33 from bottom entry tube 35 to reaction chamber 10. For example,referring to FIG. 3, a flow restrictor 150, shown in verticalcross-section, is located in the center of bottom entry tube 35 ofvortex reactor 600. In the embodiment shown in FIG. 3, flow restrictor150 is bi-conical, and thus diamond-shaped, as viewed in a verticalcross-section. The base or horizontal cross-section of the widestportion of flow restrictor 150 is preferably circular when flowrestrictor 150 is located in a circular bottom entry tube 35, to providea uniform spacing at a given height between flow restrictor 150 and thewall of the bottom entry tube 35. Similarly, if the bottom entry tube 35has a square cross-section, the horizontal cross-section of the widestportion of the flow restrictor 150 is preferably square to againmaintain a substantially uniform size of the gap portion of 140 betweenflow restrictor 150 and the walls of bottom entry tube 35. Flowrestrictor 150 may also be located in reaction chamber 10, or partiallyin reaction chamber 10 and partially in bottom entry tube 35.

Still referring to FIG. 3, multiple nozzles 60 may be positioned suchthat vortex gas flow 38 is created below gap 140 for improvedacceleration of the gas. Improved acceleration of the gas is obtained byforcing the gas of the vortex gas flow 38 to pass through the relativelynarrow portion of gap 140 between flow restrictor 150 and the walls ofbottom entry tube 35, thereby accelerating the gas.

Flow restrictor 150 may have any shape that is suitable for reducing theeffective diameter of bottom entry tube 35, while permitting at leastaxial gas flow 33 past or through flow restrictor 150. Many such objectsare conventional in the field of fluid mechanics, including, withoutlimitation, conical and bi-conical objects that create Venturi flow;spheres; and truncated bi-conical objects that are trapezoidal, asviewed in a vertical cross-section.

Non-equilibrium low-temperature plasma reactions are a highly efficientmethod for processing solid particles. Accordingly, FIG. 3 presents anembodiment of a vortex reactor 600 in which vortex reactor 600 isequipped to generate plasma to assist in improving fluidized bedprocessing. Flow restrictor 150 functions as a first electrode, and thesidewall of the frustum-shaped portion 20 functions as a secondelectrode. Voltage is applied from an external source, not shown, to thefirst and second electrodes to create a voltage difference between thefirst and second electrodes. A sufficient voltage difference between thefirst and second electrodes will cause a gliding electrical arc 170 tospan the distance between the first and second electrodes. Gas thatcomes in contact with the gliding electrical arc 170 may become ionizedto form plasma. It is well understood that the voltage differencerequired to generate the arc will depend on the distance between thefirst and second electrodes, and on the concentration and nature of thematter in the reaction chamber 10.

Preferably, for better performance, vortex reactor 600 is designed toprovide a gliding electrical arc 170 in the reaction chamber 10. Forthis purpose, the flow restrictor 150, which functions as the firstelectrode, can be extended using a straight rod 160 in order to spreadthe gliding electrical arc 170 upward as well as along thecircumferential direction through reaction chamber 10 as shown in FIG.3. In this manner, a gliding electrical arc can be created in reactionchamber 10.

In general, the provision of a narrow portion of gap 140 between flowrestrictor 150, acting as the first electrode, and the sidewalls of thebottom entry tube 35 or frustum-shaped portion 20 to initiate glidingelectrical arc 170, combined with a gradual increase in the size of gap140 between the first and second electrodes, is required to provide thedesired gliding electrical arc 170. Accordingly, flow restrictors of anysuitable geometry and size can be employed as the first electrode toprovide the desired gliding arc, as long as they provide the narrowportion of gap 140 and a gradual increase in the size of the gap 140.

FIG. 3 also depicts initiation point 180 and termination point 190 of agliding electrical arc that is produced between the first and secondelectrodes when vortex reactor 600 is optionally equipped for plasmageneration. A portion of gap 140 is made small, for example, about 3 mm,so that a gliding electrical arc 170 can be initiated at initiationpoint 180 with a voltage of about 10 kV DC power. The distance betweenthe first and second electrodes should increase gradually so that thegliding electrical arc 170 can glide upwardly in reaction chamber 10 tocover at least a substantial portion of reaction chamber 10, and morepreferably all of reaction chamber 10. As a result of the distancebetween the first and second electrodes increasing, gliding electricalarc 170 eventually terminates at a termination point 190 when thedistance becomes too great for gliding electrical arc 170 to cross thegap between the first and second electrodes. In this manner, alow-temperature, non-equilibrium plasma reaction can be created in thereaction chamber 10. This provides an efficient processing method forsolid particles.

Referring to FIG. 4, there is shown another alternative embodiment of avortex reactor 600 wherein flow restrictor 152 includes one or morechannels 154 in flow restrictor 152. Each channel is preferably orientedin a substantially axial direction, relative to bottom entry tube 35, asshown in FIG. 4. Channels 154 may be used to increase axial and/orcircumferential gas flow, or to alter the ratio of axial tocircumferential flow. Channels 154 may have a substantially constantdiameter or, in a more preferred embodiment as shown in FIG. 4, channels154 may taper in the axial direction from a larger diameter at the inletside 156 of channels 154 to a smaller diameter at the outlet side 158 ofthe channels 154 to thereby provide additional acceleration of the gasesflowing through channels 154.

Also shown in FIG. 4 is an electrical input 162 connected to flowrestrictor 152 for applying a voltage to flow restrictor 152 for plasmageneration. A similar electrical connection 164 is provided for applyinga voltage to the wall of frustum-shaped portion 20, as shown. Flowrestrictor 152 of FIG. 4 represents an alternative preferred flowrestrictor, which has a trapezoidal shape, as viewed in a verticalcross-section. One advantage of trapezoidal flow restrictor 152 is thatit can provide a very gradual widening of a portion of gap 140 betweenflow restrictor 152 and the walls of bottom entry tube 35 andfrustum-shaped portion 20. Also, the entire vertical length of thetrapezoidal flow restrictor 152 can be employed to gradually widen aportion of gap 140, whereas in the case of diamond-shaped flowrestrictor 150 of FIG. 1, only half of the vertical length of flowrestrictor 150 is employed to gradually widen gap 140.

FIG. 5 will now be discussed in detail. FIG. 5 shows a cross-sectionalview of a reactor 610. The reactor 610 has a negatively chargedcylindrical electrode 611 that forms a portion of chamber 10. It is tobe understood, that cylindrical electrode 611 could alternatively bepositively charged when the nozzle plate 614 is negatively charged.Electrical input 164 is connected to cylindrical electrode 611 andprovides voltage to the system.

Cylindrical electrode 611 has an optional bottom opening 615 located ona bottom portion for receiving an optional injection of an axial orvortex flow 33 of a second fluid (gas, liquid, disperse medium). Anaxial flow apparatus 617 can be comprised of gas nozzles, jets, or otherequivalent devices to release fluid (a gas, liquid, or disperse medium)into chamber 10 and can be located in or near bottom opening 615. Axialflow apparatus 617 may additionally comprise a porous bed.

On a top portion of cylindrical electrode 611 there is provided aninsulator 612. Insulator 612 is placed so that it provides insulationbetween negatively charged cylindrical electrode 611 and positivelycharged nozzle plate 614. Electrical input 162 is connected to nozzleplate 614 for providing a voltage to nozzle plate 614. Thecircumferential flow apparatus 613 provides a tangential flow 65 of afirst fluid (gas, liquid, disperse medium) injection. Circumferentialflow apparatus 613 can be comprised of nozzles, jets, special vortexchamber or a number of other coaxially installed equivalent devices torelease fluid into chamber 10. Additionally a flow restrictor (notshown) may form part of circumferential flow apparatus 613 and may beused to adjust the flow of the first fluid into chamber 10. Tangentialflow 65 creates a reverse vortex flow 620 in reactor 610.

Nozzle plate 614 is provided on the top portion of reactor 610. Nozzleplate 614 is used to control the output of reactor 610.

Several operations occur simultaneously within reactor 610 when inoperation. A tangential flow 65 of the first fluid is injected viacircumferential flow apparatus 613 into reaction chamber 10. Theinjection of tangential flow 65 creates a reverse vortex flow 620. Thisreverse vortex flow 620 initially comes down along the inside surface ofcylindrical electrode 611 and mixes with optional axial or vortex flow33 injected via opening 615 by axial flow apparatus 617. The mixing addsadditional fluid to the reverse vortex flow 620. Then reverse vortexflow 620 turns upward to the nozzle plate 614 and to the output of thereactor. At this time, electric arc 640 burns between the insidesurfaces of cylindrical electrode 611 and nozzle plate 614. The electricarc 640 is formed through the application of voltage to cylindricalelectrode 611 via electrical input 164 and voltage supplied to nozzleplate 614 via electrical input 162. Nozzle plate 614 has an oppositecharge from cylindrical electrode 611, which causes an electric arc 640to form. The voltage applied between the two electrodes 611, 614 shouldbe between 0.1 and 50 kV, preferably between 2 and 20 kV, and mostpreferably 3-10 kV. Due to the vortex, the electric arc 640 rotatesthroughout reaction chamber 10 and ionizes the fluid mixture. This heatsup the mixture and/or starts plasma chemical process.

Optionally, circumferential flow apparatus 613 can be electricallyconnected to the nozzle plate 614 or can be charged via electrical input162. In this case arc 641 can be formed between circumferential flowapparatus 613 and cylindrical electrode 611.

Optionally axial flow apparatus 617 can be electrically connected to thecylindrical electrode 611 or can be charged via electrical input 164. Inthis case the arc 642 can be formed between axial flow apparatus 617 andnozzle plate 614.

Optionally, the reaction chamber 10 consists of different electricallydisconnected parts including a cylindrical electrode 611 and anelectrode 630. In this case arc 643 can be formed between cylindricalelectrode 611 and electrode 630, as shown in FIG. 6. Electrode 630 canbe charged via electrical input 163.

A vortex reactor (TSAPG) with a cylindrical electrode can be used forseveral different applications: thermal spray deposition chemicaltechnology; waste treatment; metallurgy; plasma-assisted combustiondevices; igniters and pilot flames for turbine engines, boilers,burners, furnaces, etc.

The electrode life cycle for almost all direct current (DC) oralternative current (AC) plasma reactors is now the main restriction ontheir application. The combination of a reverse vortex plasma reactordevice (TGAPG) with a cylindrical electrode creates a device that has awider range of operational parameters, a dramatically increased lifecycle of the electrode, the ability to reduce electric arc powerconsumption, and reduced NOx formation in case of air as a workingmedium (the first fluid).

It is to be understood that various features of the differentembodiments shown in the drawings may be combined with one another in areverse vortex reactor (TGAPG) in accordance with the present invention.

Materials and specifications suitable for constructing a vortex reactorin accordance with the present invention are well known to those ofskill in the art. The current strength should be less than 10000 Amps,preferably less than 100 Amps and most preferably less than 1 Amp. Thecone angle of the frustum-shaped reactor, which is the angle between avertical line and the wall of the inclined reactor, should be in a rangeof 5 to 45 degrees, when the frustum-shaped reactor is upright.

In a second aspect, the present invention relates to a method for theprocessing of solid particulates in a vortex reactor. The methodincludes the steps of introducing solid particles into said reactionchamber, subjecting said solid particles to a vortex gas flow created bya combination of a circumferential gas flow and an axial gas flow, andprocessing said solid particles by drying, mixing, coating, heating,peeling, or chemical reaction.

In the method, the steps of feeding gas may create the axial fluid flowin an axial direction into said reaction chamber and accelerating saidaxial gas flow through a flow restriction. The circumferential gas flowmay be created by the step of feeding gas into said reaction chamber ina direction tangential to a sidewall of said reaction chamber, oralternatively, when the vortex reactor includes a bottom entry tube, byfeeding gas into said bottom entry tube in a direction tangential to asidewall of said bottom entry tube at a location below the flowrestriction.

The method may further include the step of generating plasma in saidreaction chamber. The step of generating plasma in said reaction chambermay include the step of providing a gliding electrical arc in saidreaction chamber, as discussed above. A reverse vortex flow, asdiscussed above, may also be provided in the method of the presentinvention.

It is to be understood that even though numerous characteristics andadvantages of the present invention have been set forth in the foregoingdescription, together with details of the structure and function of theinvention, the disclosure is illustrative only, and changes may be madein detail, especially in matters of shape, size and arrangement of partswithin the principles of the invention to the full extent indicated bythe broad general meaning of the terms in which the appended claims areexpressed.

1. A vortex reactor, comprising: a substantially frustum-shaped portionforming a reaction chamber therein, said frustum-shaped portion having anarrower part that is downwardly oriented; an axial flow apparatusfluidly connected to the reaction chamber for creating an axial gas flowin said reaction chamber; a circumferential flow apparatus fluidlyconnected to the reaction chamber for creating a circumferential gasflow in said reaction chamber; and a solid particulate inlet connectedto said reaction chamber.
 2. The vortex reactor of claim 1, wherein saidaxial flow apparatus comprises a gas supply and an apparatus selectedfrom the group consisting of a porous bed and a flow restrictor.
 3. Thevortex reactor of claim 2, wherein said flow restrictor furthercomprises at least one channel therein which provides a fluid connectionbetween said gas supply and said reaction chamber.
 4. The vortex reactorof claim 3, wherein said circumferential flow apparatus is located belowsaid flow restrictor.
 5. The vortex reactor of claim 4, wherein across-sectional area of said at least one channel tapers from a first,cross-sectional area at an end of the channel that is fluidly connectedto said gas supply, to a smaller, second, cross-sectional area at an endof the channel that is fluidly connected to the reaction chamber.
 6. Thevortex reactor of claim 1, wherein said apparatus for creatingcircumferential gas flow comprises a gas supply and one or more gasinlet nozzles oriented tangentially relative to a sidewall of thenarrower part of said frustum-shaped portion.
 7. The vortex reactor ofclaim 1, wherein said reactor further comprises a bottom entry tubefluidly connected to said reaction chamber at the narrower part of saidfrustum-shaped portion, and said apparatus for creating circumferentialgas flow comprises a gas supply and one or more gas inlet nozzlesoriented tangentially relative to a sidewall of the bottom entry tube.8. The vortex reactor of claim 2, further comprising apparatus forgenerating plasma.
 9. The vortex reactor of claim 8, comprising a flowrestrictor which functions as a first electrode for plasma generation,wherein a sidewall of said frustum-shaped portion functions as a secondelectrode for plasma generation, and wherein said apparatus forgenerating plasma comprises an apparatus for applying a first voltage tosaid first electrode and an apparatus for applying a second, differentvoltage to said second electrode.
 10. The vortex reactor of claim 9,wherein said flow restrictor is positioned to provide a small gapbetween said first and second electrodes for initiation of a plasmagenerating electrical arc at said small gap, and said flow restrictor isshaped to provide a gradual increase in the size of said gap betweensaid first and second electrodes in an upward direction to provide agliding arc in said reaction chamber.
 11. A vortex reactor as claimed inclaim 10, further comprising at least one flow restrictor located in anupper central portion of said reaction chamber for the purpose ofimpeding downward flow of gas in a central portion of said reactionchamber.
 12. A method for fluidization treatment of solid particles,comprising the steps of providing a vortex reactor, said vortex reactorcomprising: a substantially frustum-shaped portion forming a reactionchamber therein, said frustum-shaped portion having a narrower part thatis downwardly oriented, and an upper portion, an axial flow apparatusfluidly connected to the reaction chamber for creating an axial gas flowin said reaction chamber, a circumferential flow apparatus fluidlyconnected to the reaction chamber for creating a circumferential gasflow in said reaction chamber, and a particulate solids inlet connectedto said reaction chamber; introducing solid particles into said reactionchamber; subjecting said solid particles to a vortex gas flow created bya combination of a circumferential gas flow and an axial gas flow; andprocessing said solid particles.
 13. The method of claim 12, whereinsaid axial gas flow is created by the steps of feeding gas in an axialdirection into said reaction chamber and accelerating said axial gasflow through a flow restriction.
 14. The method of claim 13, whereinsaid circumferential gas flow is created by the step of feeding gas intosaid reaction chamber in a direction tangential to a sidewall of saidreaction chamber.
 15. The method of claim 13, wherein said vortexreactor further comprises a bottom entry tube, said flow restriction islocated in said bottom entry tube and said circumferential gas flow iscreated by the step of feeding gas into said bottom entry tube in adirection tangential to a sidewall of said bottom entry tube at alocation below said flow restriction.
 16. The method of claim 15,further comprising the step of generating plasma in said reactionchamber.
 17. The method of claim 16, wherein the step of generatingplasma in said reaction chamber comprises the step of providing agliding electrical arc in said reaction chamber.
 18. A vortex reactor,comprising: a substantially cylindrical shaped portion forming areaction chamber therein, wherein said substantially cylindrical shapedportion forms a first charged electrode; a circumferential flowapparatus fluidly connected to the reaction chamber for creating acircumferential fluid flow; a second charged electrode; and an outletfor releasing said circumferential fluid flow.
 19. The vortex reactor ofclaim 18, further comprising an axial flow apparatus fluidly connectedto said reaction chamber for creating an axial fluid flow in saidreaction chamber.
 20. The vortex reactor of claim 19, wherein said axialflow apparatus comprises a gas supply and an apparatus selected from thegroup consisting of a porous bed and a flow restrictor.
 21. The vortexreactor of claim 18, wherein said circumferential fluid flow apparatusis proximate to said outlet.
 22. The vortex reactor of claim 18, whereinsaid outlet comprises a nozzle plate located at a first end of saidcylindrical chamber.
 23. The vortex reactor of claim 22, wherein saidsecond charged electrode forms a portion of said nozzle plate.
 24. Thevortex reactor of claim 18, further comprising an axial flow apparatusfluidly connected to said reaction chamber for creating an axial orswirl fluid flow near an axis of said reaction chamber; and located at asecond end of said cylindrical chamber.
 25. The vortex reactor of claim18, wherein an insulator is provided between said first chargedelectrode and said circumferential flow apparatus.
 26. The vortexreactor of claim 18, wherein said apparatus for creating circumferentialfluid flow comprises a gas supply and one or more gas inlet nozzlesoriented tangentially relative to a sidewall of said cylindrical shapedportion.
 27. The vortex reactor of claim 18, wherein said reactorfurther comprises an axial flow apparatus fluidly connected to saidreaction chamber, and said apparatus for creating circumferential fluidflow comprises a fluid supply and one or more fluid inlet nozzlesoriented tangentially relative to a sidewall of a bottom entry tube. 28.The vortex reactor of claim 18, further comprising an apparatus forgenerating plasma.
 29. The vortex reactor of claim 18, wherein saidcircumferential flow apparatus generates an axially-symmetriccircumferential fluid flow.
 30. The vortex reactor of claim 18, whereinsaid circumferential flow apparatus further comprises an electricalinsulator.
 31. The vortex reactor of claim 18, wherein said secondcharged electrode forms part of said circumferential flow apparatus andan electrical arc is formed between said first charged electrode andsaid second charged electrode.
 32. The vortex reactor of claim 18,wherein said second charged electrode is formed at different portion ofsaid substantially cylindrical shaped portion than said first chargedelectrode and an electrical arc is formed between said first chargedelectrode and said second charged electrode.